Generally, in an extracorporeal circulation apparatus such as the artificial heart-lung machine described in JP-A-2006-325750, a status value related to blood flowing inside a circulation circuit is obtained and monitored. Furthermore, a device in the apparatus, such as the pump provided in the circulation circuit of the machine described in JP-A-2006-325750, is controlled based on the result thereof.
In utilizing such an extracorporeal circulation apparatus, the pump can be operated by setting a flow rate (volume of flowing blood per unit time) in which a physique and the like of a patient are considered. In addition, a flow rate sensor provided on the circulation circuit detects the actual flow rate, and threshold values (an upper limit value and a lower limit value) for determining whether the flow rate is appropriate are also set. Furthermore, the apparatus can have a feature in which, when the flow rate detected by the sensor falls below the set lower limit value, an appropriate automated function such as issuance of an alarm is triggered.